After installing the Windows Phone 8.0 SDK, I've seen that the XAML designer of the Windows Phone SDK is not updating when I change a value like the Background property. I need to compile the project to see the modification in the designer. Very painful.
Anyone have an idea? The other XAML designers (Windows 8 store app/WPF) work perfectly, so it seems that it's the SDK's problem.
My configuration: Haswell i5 Intel HD 4400 4GO Ram Visual 2012 / 2013 Preview
The problem occurs in both Visual Studio and Blend. Windows 8 Store App and WPF designers work on both IDEs; only the Windows Phone designer doesn't work.
I've had the same exact problem before. If I'm not mistaken, simply uninstalling and reinstalling the SDK seemed to fix the problem.